483 research outputs found
Global Carleman inequalities for parabolic systems and applications to controllability
This paper has been conceived as an overview on the controllability properties of some relevant (linear and nonlinear) parabolic systems. Specifically, we deal with the null controllability and the exact controllability to the trajectories. We try to explain the role played by the observability
inequalities in this context and the need of global Carleman estimates. We also recall the main ideas used to overcome the difficulties motivated by nonlinearities. First, we considered the classical heat equation with Dirichlet conditions and distributed controls. Then we analyze recent extensions to
other linear and semilinear parabolic systems and/or boundary controls. Finally, we review the controllability properties for the Stokes and Navier–Stokes equations that are known to date. In this context, we have paid special attention to obtaining the necessary Carleman estimates. Some open questions are mentioned throughout the paper. We hope that this unified presentation will be useful for those researchers interested in the field.Ministerio de Educación y Cienci
South Korea's automotive labour regime, Hyundai Motors’ global production network and trade‐based integration with the European Union
This article explores the interrelationship between global production networks(GPNs) and free trade agreements (FTAs) in the South Korean auto industry and its employment relations. It focuses on the production network of the Hyundai Motor Group (HMG) — the third biggest automobile manufacturer in the world — and the FTA between the EU and South Korea. This was the first of the EU’s ‘new generation’ FTAs, which among other things contained provisions designed to protect and promote labour standards. The article’s argument is twofold. First, that HMG’s production network and Korea’s political economy (of which HMG is a crucial part) limited the possibilities for the FTA’s labour provisions to take effect. Second, that the commercial provisions in this same FTA simultaneously eroded HMG’s domestic market and corporate profitability, leading to adverse consequences for auto workers in the more
insecure and low-paid jobs. In making this argument, the article advances a multiscalar conceptualization of the labour regime as an analytical intermediary between GPNs and FTAs. It also provides one of the first empirical studies of the EU–South Korea FTA in terms of employment relations, drawing on 105 interviews with trade unions, employer associations, automobile companies and state officials across both parties
Dissipative structure formation in cold-rolled Fe and Ni during heavy ion irradiation
We report 4-probe resistivity measurements of cold-rolled Ni and Fe during
100 MeV oxygen ion irradiation, at 300K. The resistivity shows increase and
saturation, marked by jumps. Employing 200 MeV silver ion irradiation of Fe and
Si(100) and topographically identifying strain at an artificial interface in
the latter, we assign the resistivity behavior to atomic rearrangements arising
from dissipation of incident ion energy at internal interfaces of Ni and Fe,
with positive feedback.}Comment: RevTex+ 7 Postscript figures; Fig 2 (topograph) available on demand
to [email protected]. To appear in Phys Rev Let
Carboxymethyl guar gum nanoparticles for drug delivery applications: preparation and preliminary in-vitro investigations
Abstract Carboxymethyl guar gum (CMGG) synthesised from commercially available polysaccharide was formulated into nanoparticles via ionic gelation using trisodium trimetaphosphate (STMP) as cross-linking agent. Characterisation using a range of analytical techniques (FTIR, NMR, GPC, TGA and DLS) confirmed the CMGG structure and revealed the effect of the CMGG and STMP concentration on the main characteristics of the obtained nanoformulations. The average nanoparticle diameter was found to be around 208 nm, as determined by dynamic light scattering (DLS) and confirmed by scanning electron microscopy (SEM) and nanoparticle tracking analysis (NTA). Experiments using simulated gastric and intestinal fluids evidenced significant pH-dependent drug release behaviour of the nanoformulations loaded with Rhodamine B (RhB) as a model drug (loading capacity in excess of 83%), as monitored by UV-Vis. While dose-dependent cytotoxicity was observed, the nanoformulations appeared completely non-toxic at concentrations below 0.3 mg/mL. Results obtained so far suggest that carboxymethylated guar gum nanoparticles formulated with STMP warrant further investigations as polysaccharide based biocompatible drug nanocarriers
The drivers of change for the contribution of small farms to regional food security in Europe
The capacity of the food system to respond to the economic, demographic and environmental challenges ahead has become a topic of increasing interest, with particular attention to the roles and responsibilities of the different actors to ensure more sustainable food systems that can guarantee food and nutrition security for all. In this paper we approach the need to better understand the factors that can condition the potential contribution of small farms to regional food and nutrition security in Europe, acknowledging the role that small farms play in Europe at present. The analysis is based on a survey to 94 experts from 17 regions (NUTS3 level) in 11 different European countries, which identified the drivers of change according to the regional experts. These drivers were then categorized and their relative relevance assessed. The results indicate that some relevant drivers in the European context are linked to the capacity to adopt technologies and practices allowing adaptation to climate change, and the capacity to connect to food markets, with emphasis in the need for cooperation and collective action. The weight of other more European-specific drivers such as ‘consumer values and habits’ reveal that the future role of small farms will be very dependent on a societal change, with equity becoming a relevant component of consumers’ choice
Excited States of Proton-bound DNA/RNA Base Homo-dimers: Pyrimidines
We are presenting the electronic photo fragment spectra of the protonated
pyrimidine DNA bases homo-dimers. Only the thymine dimer exhibits a well
structured vibrational progression, while protonated monomer shows broad
vibrational bands. This shows that proton bonding can block some non radiative
processes present in the monomer.Comment: We acknowledge the use of the computing facility cluster GMPCS of the
LUMAT federation (FR LUMAT 2764
Automated Classification of Depression from Structural Brain Measures across Two Independent Community-based Cohorts
ACKNOWLEDGEMENTS: This study was supported and funded by the Wellcome Trust Strategic Award ‘Stratifying Resilience and Depression Longitudinally’ (STRADL) (Reference 104036/Z/14/Z), and the Medical Research Council Mental Health Pathfinder Award ‘Leveraging routinely collected and linked research data to study the causes and consequences of common mental disorders’ (Reference MRC-MC_PC_17209). MAH is supported by research funding from the Dr Mortimer and Theresa Sackler Foundation. The research was conducted using the UK Biobank resource, with application number 4844. Structural brain imaging data from the UK Biobank was processed at the University of Edinburgh Centre for Cognitive Ageing and Cognitive Epidemiology (CCACE) http://www.ccace.ed.ac.uk/), which is a part of the crosscouncil Lifelong Health and Wellbeing Initiative (MR/K026992/1). CCACE received funding from Biotechnology and Biological Sciences Research Council (BBSRC), Medical Research Council (MRC), and was also supported by Age UK as part of The Disconnected Mind project. This work has made use of the resources provided by the Edinburgh Compute and Data Facility (ECDF) (http://www.ecdf.ed.ac.uk/)Peer reviewedPublisher PD
Approximate Controllability for Linear Stochastic Differential Equations in Infinite Dimensions
The objective of the paper is to investigate the approximate controllability
property of a linear stochastic control system with values in a separable real
Hilbert space. In a first step we prove the existence and uniqueness for the
solution of the dual linear backward stochastic differential equation. This
equation has the particularity that in addition to an unbounded operator acting
on the Y-component of the solution there is still another one acting on the
Z-component. With the help of this dual equation we then deduce the duality
between approximate controllability and observability. Finally, under the
assumption that the unbounded operator acting on the state process of the
forward equation is an infinitesimal generator of an exponentially stable
semigroup, we show that the generalized Hautus test provides a necessary
condition for the approximate controllability. The paper generalizes former
results by Buckdahn, Quincampoix and Tessitore (2006) and Goreac (2007) from
the finite dimensional to the infinite dimensional case.Comment: 31 pages, submitted to AM
Hair glucocorticoids are associated with childhood adversity, depressive symptoms and reduced global and lobar grey matter in Generation Scotland
ACKNOWLEDGEMENTS We would like to thank all of the Generation Scotland participants for their contribution to this study. We also thank the research assistants, clinicians and technicians for their help in collecting the data. Generation Scotland received core support from the Chief Scientist Office of the Scottish Government Health Directorates [CZD/16/6] and the Scottish Funding Council [HR03006] and is currently supported by the Wellcome Trust [216767/Z/19/Z]. This study was also supported and funded by the Wellcome Trust Strategic Award ‘Stratifying Resilience and Depression Longitudinally’ (STRADL) (Reference 104036/Z/14/Z). We acknowledge the support of the British Heart Foundation (RE/18/5/34216). CG is supported by the Medical Research Council and the University of Edinburgh through the Precision Medicine Doctoral Training Programme. MCB is supported by a Guarantors of Brain Non-Clinical Post-Doctoral Fellowship. JMW is funded by the UK Dementia Research Institute which is funded by the UK Medical Research Council, Alzheimer’s Research UK and Alzheimer’s SocietyPeer reviewedPublisher PD
Liver retransplantation as a therapeutic method in graft dysfunctions in the immediate postoperative period
Departament Chirurgie Generală, I.C. Fundeni, București, România, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și
al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaCu toate că în ultimii ani au apărut progrese importante în domeniul hepatic, problema prevenirii apariției disfuncției și eșecului
post-transplant nu a prezentat progrese semnificative. Intrucât disfuncția hepatică primară influențează dramatic evoluția grefei
și a pacientului transplantat hepatic, prevenirea acestui fenomen devine obligatoriu. Creșterea penuriei de organe și a numărului
persoanelor aflate pe lista de așteptare a dus la folosirea unor grefe ce depășesc criteriile normale de selecție pentru recoltare
precum și transplantarea unor donatori considerați marginali. Aceste circumstanțe au adus în prim plan importanța diagnosticării și
tratamentului disfuncției hepatice primare.
Conceptul de disfuncție hepatică primară nu este clar definit. Există un spectru de evenimente ce definesc disfuncția hepatică
postoperatorie precoce: non funcția primară (PNF), nonfuncția întârziată, funcția slabă/săracă inițială (initial poor function – IPF), non
funcția inițială, insuficiența hepatică primară și disfuncția primară. Distincția între aceste entități ia în considerare gradul disfuncției
hepatice, necesitatea retransplantării urgente, precum și apariția și durata acestor evenimente după transplantul hepatic.Although important progress has been made over the last few years, the problem of preventing dysfunction and post-transplant liver
failure has not shown significant progress. Since primary liver dysfunction dramatically influences the progress of the graft and the
liver transplant patient, prevention of this phenomenon becomes obligatory. The increase in organ shortage and the number of people
on the waiting list led to the use of grafts that exceeded the normal selection criteria for harvesting as well as the transplantation of
marginal donors. These circumstances have highlighted the importance of diagnosis and treatment of primary hepatic dysfunction.
The concept of primary liver dysfunction is not clearly defined. There is a spectrum of events that defines early postoperative liver
dysfunction: primary non-function (PNF), delayed dysfunction, initial poor function (IPF), primary hepatic failure, and primary dysfunction.
The distinction between these entities takes into account the degree of hepatic dysfunction, the need for urgent retransplantation, and
the occurrence and duration of these events after liver transplantation
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